a workflow-based architecture for e-learning in the grid
DESCRIPTION
A Workflow-based Architecture for e-Learning in the Grid. Luiz A. Pereira, Fábio A. Porto, Bruno Schulze, Rubens N. Melo {lpereira,rubens}@inf.puc-rio.br, {fporto,schulze}@lncc.br. Agenda. Introduction/Motivation Description of the Environment Description of the Architectural Model - PowerPoint PPT PresentationTRANSCRIPT
CLAG 2004 – April/04 1
A Workflow-based Architecture for e-Learning in the Grid
Luiz A. Pereira, Fábio A. Porto, Bruno Schulze, Rubens N. Melo{lpereira,rubens}@inf.puc-rio.br, {fporto,schulze}@lncc.br
CLAG 2004 – April/04 2/21
Agenda
Introduction/Motivation
Description of the Environment
Description of the Architectural Model
Related and Future Works and Concluding Remarks
CLAG 2004 – April/04 3/21
Introduction/MotivationMotivation: PGL (Partnership In Global Learning) Project
(PUC/UF) Many partners providing learning content in a global scale:
data distribution, technological heterogeneity, easy and cost effective content access.
e-Learning scenarios requiring computational-intensive learning objects for simulation purposes (LNCC) Fluid mechanics course containing the simulation of a fluid
path, which requires the computation of virtual particles trajectories (applied to hemodynamics)
CLAG 2004 – April/04 4/21
Introduction/Motivation
Requisites: Effective e-learning environments should promote high
cooperation. Benefits: in the cognitive domain, improving learning capacity and academic
performance. in social and affective ones – improving group and individual self-
confidence. It is important to consider new methods to reduce learning content
development costs. It is also important to consider (cost) effective content delivery
mechanisms. Many cases requiring massive computing power and/or data
storage usually not available in a single workstation.
CLAG 2004 – April/04 5/21
Introduction/MotivationProposed Solution: Cooperation WfMS, providing:
Executor-task assignments Effective interaction coordination Execution duration control and synchronization Coordination of the execution of tasks involving massive
computation and/or data processing. Content development cost reduction use of modular
and reusable learning modules (LOs): To facilitate deployment and execution assignment Reusability and standardization contributing to content
development costs reduction and quality improvement.
CLAG 2004 – April/04 6/21
Introduction/Motivation Proposed Solution(cont.):
(Cost) effective content delivery mechanisms Web based environment
Massive computing power and/or data storage Grid
CLAG 2004 – April/04 7/21
Introduction/Motivation
TEAM is both An architectural model: Teamwork-support
Environment Architectural Model Operating environments based on the
architectural model: Teamwork Applications Manager
CLAG 2004 – April/04 8/21
Introduction/Motivation
TEAM (the architectural model): TEAMA
TEAM (the environment): TEAME, instantiated to e-learning.
CLAG 2004 – April/04 9/21
Description of TEAME
Students and teachers would execute instructional steps cooperatively guided by a WfMS
WfMS deals transparently with distribution, autonomy and technological heterogeneity of the content repositories that are located in the partners’ sites
Content is LO-oriented and is described using the IEEE-LOM standard.
CLAG 2004 – April/04 10/21
Description of TEAME
The processing unit of the environment is called a peer, working as a gateway to environment Provides user’s authentication, User-environment interaction control, Execution context management.
Each user is associated to a peerA site is a logical collection of peers sharing a common learning purposeUsers have transparent access to resources within sites in which his home peer is included
CLAG 2004 – April/04 11/21
Description of TEAME
The environment is logically divided in two scopes, external and internal, according to user roles.
CLAG 2004 – April/04 12/21
Description of TEAME
The external scope: Provides an environment for students accessing
courses they are registered to attend. External users “see” the (distributed)
environment as just one piece The workflow enactment services provide this
transparent vision to external users, routing, retrieving and allocating resources to/from proper peers
CLAG 2004 – April/04 13/21
Description of TEAME
The internal scope: Refers to the working context of the
environment’s the internal users: Technical support staff, Application developers, Database administrators and Learning content developers
CLAG 2004 – April/04 14/21
Description of TEAME
The distributed e-learning environment scopes
Peer 1
…
Peer 2
Peer 4
Peer 3
Internal Users
External Users
Internal Users
CLAG 2004 – April/04 15/21
Description of TEAME
What about content? It is LO-oriented Developed in “reusable modules” from scratch
and/or Developed by aggregating LOs developed by
other partners Lightweight or Heavyweight, requiring Grid resources
CLAG 2004 – April/04 16/21
Description of TEAMA
Architecture based on mediator(s) and wrappersPeers are functionally identical but some of them run on top of a grid (operating) system to access resources provided by grid environment(s).Grid resources management to be done transparently from the user perspective
CLAG 2004 – April/04 17/21
Site 1Site 2
Site 3Site 4
P1 P2 P3
P4P5P6
Grid 1
Grid 2
Description of TEAMA
TEAMA conceptual view
TEAM Connection
Grid Connection
CLAG 2004 – April/04 18/21
Description of TEAMA
Each peer in TEAMA is a stack of three layers (a 3-tier architectural model) User Interface, Workflows services (business processes/rules) Other services (data persistence, resource
scheduling, …) .
CLAG 2004 – April/04 19/21
Description of TEAMA
TEAM 3-tier architecture
User interface with the environment:a web browser or a .NET application.
The functional core of the architecture:The workflow enactment service managing a convenient portion of the whole workflow instance.
Service layer provides data persistenceand grid access for heavyweight tasks.
ApplicationApplicationBrowserBrowser
User associated to site i
Web services for data sources access
Web services for data sources access
Control
Data
Metadata
JSPJSP
Web services
Workflow enactment service
Grid
CLAG 2004 – April/04 20/21
Related and Future Works and Concluding Remarks
At LNCC we are developing a grid infrastructure to be used transparently from several kinds of applications.
One of these types of applications is an e-Learning Management System capable of sharing distributed e-learning modular content and controlling student-student and student-teacher collaboration.
CLAG 2004 – April/04 21/21
Related and Future Works and Concluding Remarks
TEAM extension towards its integration with grid infrastructure is at its initial phase. We need to integrate user authentication between
TEAM and the grid We need to develop a more refined authorization policy
that will include information on user rights to access a LO
We need to extend our current LO storage and query services
We need to refine how our search for LOs will be implemented
We need to improve workflow specification to work on a non-structured scenario